Insert having hollow locking pins



May 16, 1967 J. Ros/ 1M ETAL INSERT HAVING HOLLOW LOCKING PINS 3 Sheets-Sheet 1 Filed Oct. 22, 1965 INVENTOR. ase' K756i! Marv/r2 Reese @mM @460 y 1967 J. Ros/iN ETAL 3,319,888

INSERT HAVING HOLLOW LOCKING PINS Filed Oct. 22, 1965 5 Sheets-Sheet 2 INVENTOR.

Jo se Fvsarz Mary/ll 1? Reese J QIVEF y 6, 1967 J. ROSAN ETAL 3,319,688

INSERT HAVING HOLLOW LOCKING PINS Filed Oct. 22, 1965 5 Sheets-Sheet Z INVBNTOR. fos Kwa'n Mqrvm Reese ATTORNEY United States Patent 3,319,6538 INSERT HAVING HQLLUW LGCKING PINS .l'os Rosin, San Juan Capistrano, and Marvin I. Reece,

Dana Point, Caiif., assignors to Rosana Engineering Corp, Newport Beach, Calif, a corporation of California Filed Oct. 22, 1965, Ser. No. 509,252 6 Claims. (Cl. fill-23) This application is a continuation-in-part of my copending application, Ser. No. 430,329, entitled, Insert Having Hollow Locking Pins, which was filed on Feb. 4, i965, and is now abandoned.

This invention relates generally to improvements in inserts having external threads for mounting the same in a workpiece and to a method of making same.

More particularly, the invention concerns inserts designed to be anchored in bores in relatively softer material and to a method of making same. The invention finds particular usefulness where assurance is necessary that the insert will not loosen or fail, either by axial or rotational displacement. Hence, the present invention is provided with novel locking means to positively maintain it in its installed position.

The locking means which prohibits rotational displacement of the present insert comprises one or more hollow locking pins, individually positioned in longitudinal grooves located on the insert body. The locking pin is installed so that at least a portion thereof is adapted to be accommodated within the aforesaid longitudinal insert groove. Prior to locking the insert against rotation thereof, the pin is maintained in a first or inoperative position, securely accommodated in said groove and axially projecting above the insert. While the pin is in its first or inoperative position axially projecting above the insert, said pin may be engaged by an accommodating tool, so that the insert may be rotatably threaded into the workpiece bore.

Upon the application of an axial downward force on the top of the pin, said pin is axially displaced into a second or operative position into the longitudinal groove provided by the insert body, and simultaneously shears away a portion of the internal threads of the bore in the workpiece. The material of the bore threads thus sheared away, is displaced upwardly through the hollow cavity of the pin, thereby accommodating any chipped material or debris from the bore cavity, yet avoiding the expelling of said chips or debris to the workpiece surface.

This axial displacement of the pin into its operative position provides a secure, efiicient and simple means for locking the insert against further rotational movement.

The hollow locking pin herein referred to may be round, oval, square, or oblong, provided it is hollow and it conforms to the features hereinafter described.

When fully displaced into the longitudinal groove provided by the insert body, the outermost tangential point of the pin should not exceed the minimum major diameter (root) of the threads of the workpiece bore in which the insert is threaded, nor should the innermost tangential point of the pin intersect the maximum major diameter (root) of the internal threads in the case of an internally threaded hollow insert or the solid body portion of a stud type insert. With this general size limitation in mind, it can be seen that as the size of an insert increases, the size of the pin capable of being used in said insert can also be increased, thereby increasing the resistance to rotational force (torque) of the insert once the pin is axially displaced into its operative or locked position.

Accordingly, the principal object of the invention is to provide an improved, simple insert of inexpensive construction, capable of being permanently locked in a workpiece and capable of being installed and locked into place by extremely simple tools.

Another object-is to provide an insert having locking means preventing rotational movement and capable of being installed and locked into a workpiece bore which is not provided with a counterbore.

Another object is to provide an insert having a locking means for locking same by intersecting the threads of the workpiece bore, yet capable of being freely threaded into said bore.

Still another object of the invention is to provide an insert capable of having the insert body stationary and unaffected while the pin lock is axially displaced into locking position.

A further object is to provide an insert with a lock which has greater torque resistance than prior inserts of the same type.

Still a further object is to provide a special insert embodying a stud.

Another object is to provide a method of making an insert having a means for locking same by intersecting the threads of the workpiece bore, yet capable of being freely threaded into said bore.

Other objects and advantages of the invention will become apparent from the description taken in conjunction with the following drawings, in which:

FIG. 1 is an enlarged, elevational, partly sectioned view of the insert embodying the principles of the present invention, showing the insert threaded into a bore in a workpiece and having a pluarilty of round locking pins positioned in a first or inoperative position, prior to axial displacement of same into the threads of said Workpiece bore;

FIG. 2 is an enlarged, elevational, partly sectioned view of the insert of FIG. 1 in fully locked position, having the locking pin thereof axially displaced into an operative or locked position into the threads of the workpiece bore;

FIG. 3 is an enlarged, top plan view of the insert of FIG. 1;

FIG. 4 is a greatly enlarged, sectioned side view of the locking pin of FIGS. 1-3;

FIG. 5 is a greatly enlarged, bottom plan view of the locking pin of FIG. 4;

FIG. 6 is an enlarged, top plan view similar to FIG. 3, but with the locking pins removed and showing internal drive grooves as alternate means for threading the insert of FIG. 1 into a bore in a workpiece;

FIG. 7 is a greatly enlarged, sectioned side view of a square configured embodiment of the locking pin of the present invention;

FIG. 8 is a greatly enlarged, bottom plan view of the locking pin of FIG. 7;

FIG. 9 is a greatly enlarged, top plan view of an insert similar to that of FIG. 1, but having the longitudinal grooves thereof adapted to accommodate the embodiment of the locking pin of FIG. 7;

FIG. 10 is a greatly enlarged, sectioned side view of an oval configured embodiment of the locking pin of the present invention;

FIG. 11 is a greatly enlarged, bottom plan view of the locking pin of FIG. 10;

FIG. 12 is a greatly enlarged, top plan view of an insert similar to that of FIG. 1, but having the longitudinal grooves thereof adapted to accommodate the embodiment of the locking pin of FIG. 10;

FIG. 13 is a greatly enlarged, sectioned side view of another embodiment of an oval configured locking pin of the present invention;

FIG. 14 is a greatly enlarged, bottom plan view of the locking pin of FIG. 13;

FIG. 15 is a greatly enlarged, top plan view of an insert similar to that of FIG. 1, but having the longitudinal grooves thereof adapted to accommodate the embodiment of the locking pin of FIG. 13;

FIG. 16 is an enlarged, elevational, partly sectioned view of a stud type insert embodying the principles of the present invention and having locking pins as illustrated in FIGS. 14;

FIG. 17 is an enlarged, top plan view of the insert of FIG. 16; and

FIG. 18 is a perspective view of the insert of FIG. 1, except that the external threads thereof are rerolled so as to provide retaining shoulders adjacent the grooves.

Referring more particularly to FIGS. 1 and 2, numeral 20 designates generally a workpiece having an outer surface 21. As illustrated, the workpiece 20 is formed with a threaded bore 22 extending inwardly from the outer surface 21.

The insert is constructed of any suitable material relatively harder than the workpiece 20 and is generally identified by numeral 23, said insert comprising a tubular body 24 provided with external threads 25 and a threaded bore 26.

Longitudinal grooves 27 provided by insert 23 intersect external threads 25 thereof and have a radial depth extending inwardly into the insert body from the crest 28 of external threads 25.

Locking pins 30, having a hollow enclosed cavity 31 and an abutment shoulder 32, are rigidly attached to insert body 24. Said locking pins are also provided with a tapered section 33 which is snugly accommodated in grooves 27.

It should be noted that locking pins 30 are accommodated in grooves 27 so that the center lines thereof are located radially inwardly of the minimum major diameter of external threads 25 of the insert body 24 in order to prevent the looking pins from rolling out of their locked position upon the application of a rotational force to the insert. This, of course, is particularly true with respect to the cylindrical tubular configuration of the locking pins illustrated in FIGS. 1-5 and the oval configuration of the locking pins illustrated in FIGS. 10, 11, 13 and 14.

It should be further noted that the maximum diameter of the tapered section 33 of pins 30 is such that when accommodated in grooves 27 prior to being longitudinally displaced therein, said tapered section does not interfere with the crests 38 of the threads of the workpiece bore 22 when the insert is threaded therein. As indicated above, however, when pins 30 are axially displaced, shoulders 32 will shear a portion of crests 38 and accommodate such sheared material in the hollow cavity 31 thereof.

Pins 30, as shown in FIG. 1, are in a first, or inoperative, position prior to being axially displaced into locking engagement with the threads of the workpiece bore. When pins 30 are in the position illustrated in FIG. 1, they may be engaged 'by a suitable driving tool so that insert 23 may be threaded into threaded bore 22 of the workpiece.

Insert 23 is threaded into bore 22 until the abutment shoulder 32 carried by locking pins 30 is seated in abutting engagement upon outer surface 21 of workpiece 20. Thus, the insert is consistently uniformly seated to a predetermined depth in the workpiece.

Longitudinal grooves 27, illustrated in FIG. 1, are contoured (as best shown in FIG. 6) so that the innermost portion of the groove wall has a a configuration corresponding to that of locking pins 30. In addition, grooves 27 are provided with retaining shoulders 36. Thus, tapered section 33 of locking pins 30 is retained in said grooves by retaining shoulders 36, and abutment shoulder 32 of the locking pins 30 is seated upon said retaining shoulders.

The retaining shoulders 36 may be provided by broaching through the successive convolutions of external threads 25 of the insert, or may be provided by rerolling the roots 29 of said threads 25 so as to displace a portion of the root adjacent the walls of grooves 56 into said grooves, thereby providing a series of retaining shoulders 57 (see FIG. 18).

When an axial force is applied on the ends of locking pins 30 so as to displace the same into a locking engagement with the threads of the workpiece bore, as in FIG. 2, tapered section 33 acts as a guide means for pins 30 while they are being displaced downwardly into grooves 27 To further facilitate such displacement and also eliminate binding of the pin, tapered section 33 is further provided with a second taper 34 at the end thereof. It should be noted that when the locking pins 30 are being axially displaced, such displacement of the pins is independent of the insert body 24. That is, body 24 remains stationary so that the external threads 25 of the insert and the interengaged threads of the workpiece bore 22 are not distorted or damaged by the application of the displacement force to the locking pins.

When pins 30 are being displaced (as shown in FIG. 2), abutment shoulder 32 acts as a cutting edge which shears away a portion of the convolutions of the threaded bore 22 of the workpiece. The thread material which has thus been severed from the internal threaded bore 22 of the workpiece is accommodated in the holow cavities 31 of locking pins 30 as at 37. By accommodating the sheared material in the hollow cavities 31 of the pins 30 the possibility of jamming the pins during the axial displacement thereof is eliminated and in addition avoids distorting the workpiece bore threads in the area of engagement with the locking pins. Further, by accommodating the sheared material within the pins, another detrimental feature is eliminated in that this material is not ejected to the surface of the installed fastener.

In the instant invention the diameter or transverse dimension of the locking pins 30 may vary as the thread size varies. That is, as the external thread size increases, a locking pin having a larger cross sectional dimension may be used, thereby increasing resistance to torque subsequent to displacing the pin into its locking position. Regardless of the size or configuration of the locking pin used, the outermost tangential point 39 of the locking pin must be equal to, or less than, the major diameter of the external threads 25 of the insert. This is necessary to reduce the amount of force required to axially displace the locking pins into the operative, or fully locked, position and is accomplished by confining the shearing action of shoulders 32 to the thread convolutions of the workpiece bore rather than having said shoulders shearing through the workpiece itself. Also, for this reason, the outermost tangential points 39 of the locking pins 30 are positioned in the grooves 27 of the insert body 24 so that no portion of said pins intersect the minimum major diameter (root diameter) of the threads of threaded bore 22 of the workpiece.

As can be seen from FIG. 2, the axial displacing force is applied until the outermost ends of locking pins 30 are flush with outer surface 21 of workpiece 20. Concomitantly, the outermost ends of pins 30 are also flush with the outermost end of insert 23. When locking pins 30 are in the position shown in FIG. 2, the inter-engagement of the convolutions of the internal threaded bore 22 of the workpiece and the external threads 25 of the insert 23 by locking pins 30 provide a positive rotational resistant lock of the insert in the bore of the workpiece.

FIG. 3 is a top plan view of the insert described in FIGS. 1 and 2, and illustrates the relationship of the outermost tangential point 39 of the locking pins to the major diameter of the external threads of the insert, as above described, wherein said outermost tangential point 39 of the locking pins coincides with that of the crests 28 of the external threads of the insert at that point.

FIGS. 4 and 5 illustrate the configuration of the embodiment of the locking pins discussed with reference to FIGS. 1-3, and clearly demonstrate the tapered configuration 33 of a portion of the locking pins 30 and the second taper 34 provided at the ends thereof. As aforesaid, tapers 33 and 34 tend to guide the locking pins during the axial displacement thereof, and further, by virtue of the tapered configurations, avoid jamming the pins during this displacement.

The longitudinal grooves 27, as illustrated in FIG. 6, are contoured so that the innermost portion of the groove wall has a configuration corresponding to that of the locking pins 30, and are further provided with retaining shoulders 36. Prior to the axial displacement of locking pins 30, the tapered portion 33 thereof is confined between groove wall 35 and retaining shoulders 36. Abutment shoulders 32 of the locking pins 30 are seated upon the outermost surface of said shoulders 36 at the surface of the workpiece. Retaining shoulders 36 may be radially positioned inwardly or outwardly of the minor diameter (root diameter) of the external threads 25 of the insert. In any event, shoulders 36 of grooves 27 are positioned radially inwardly of the crests 38 of the threads of threaded workpiece bore 22 so that when tapered section 33 of pins 30 is located in said grooves prior to the axial dispalcement thereof, said tapered section does not interfere with crests 38 of the threads of the workpiece bore when the insert is threaded therein.

FIG. 6 is also illustrated with a plurality of internal drive grooves 40, whereby the insert may be threaded into the workpiece bore 22 without utilizing the projecting locking pins 30, illustrated in FIG. 1, as a driving means.

FIGS. 7 and 8 illustrate another embodiment of the locking pins 30, wherein said pins have a substantially square cross sectional configuration. The various elements of the present invention disclosed in conjunction with the previously described locking pin configuration are also present here.

In FIG. 9, the accommodating longitudinal grooves 27 of the insert body are capable of retaining the configurations of FIGS. 7 and 8 and are modified slightly so that the innermost groove wall 35 has a substantially square configuration and the open faces 41 of the keyway are provided with a slight angle (designated by A) so that body shoulders 32 of the locking pins seat upon the uppermost corner of the retaining shoulders 36, thereby reducing the amount of force and shearing action required when the locking pin is axially displaced to its fully locked position. In the event a concave or convex back wall is provided by pin 30, innermost groove wall 35 may be correspondingly contoured.

FIGS. 10 and 1'1 illustrate a further embodiment of the locking pins 30 of the present invention, wherein said pins have an elliptical cross sectional configuration and the major axis of the ellipse is adapted to be positioned in the longitudinal insert grooves 27 normal to the insert axis. This is clearly evidenced in FIG. 12 which illustrates the corresponding longitudinal groove 27 adapted to receive the locking pin configuration illustrated in FIGS. 10 and 11.

FIGS. 13 and 14 also illustrate a locking pin 30 hav ing an elliptical configuration, but which is provided with the minor diameter of the ellipse adapted to be positioned in grooves 27 normal to the insert axis.

FIG. 15 illustrates the configuration of the longitudinal insert grooves 27 which are adapted to receive the locking pin of FIGS. 13 and 14.

Except for the modifications in configuration of locking pins 30 illustrated in FIGS. 7, 8, 10, 11, 13 and 14, said locking pins embody all the essential features of the invention described with respect to the locking pins 30 of FIGS. 15 and perform substantially in the same manner.

FIG. 16 illustrates a special stud type insert 42 com bining the principles of the present invention, except that it is substantially solid throughout. Stud insert 42 is provided with a body 43 having external threads 44 and 46 thereon, which are engageable with threads 47 of the internal bore 48 of workpiece 49. Insert 42, as was the case with the inserts hereinbefore described, is also provided with locking pins 50 having a hollow cavity 51 and an abutment shoulder 52. Locking pins 54) are provided with a tapered portion 53 having a second tapered portion 54 at the end thereof. The locking pins 50 are accommodated in external longitudinal grooves 55 provided on the stud insert body similar to those of the above described inserts. As illustrated in FIG. 16, locking pins 50 are in a first, or inoperative, position prior to being displaced into locking engagement with the threads of the workpiece bore. All the elements of the present invention described in conjunction with FIGS. 16 above are contained in the stud type insert of FIG. 16 and have substantially the same relationship.

Although the stud type insert of FIG. 16 is illustrated with locking pins having a cylindrical tubular configuration, it is to be understood that the embodiments of the locking pins illustrated in FIGS. 7, 8, 10, 11, 13 and 14 may also be utilized with this stud type insert.

FIG. 17 is a top plan view of a stud type insert illustrated in FIG. 16.

The insert illustrated in FIG. 18 is similar to that of FIG. 1, except that the external threads 25 are rerolled so as to displace a portion of the surface thereof adjacent to walls of grooves 56 into said grooves, thereby providing a series of longitudinally aligned retaining shoulders 57.

To produce shoulders 57, a straight walled horizontal groove 56 having a contoured back wall 58 is provided on the external surface of the insert 23. Thereafter, the external threads 25 are lightly rerolled, causing the edge of the thread surface which is intersected by the side wall of the groove 56 to roll over so as to form a series of intermittent longitudinally aligned shoulders 57 capable of retaining the locking pins in tight association with the body of the insert.

While several embodiments of the invention and the method of using same have been described, it is of course, understood that the particular embodiments of the invention herein disclosed are for illustrative purposes only and that various changes may be made therein without departing from the principles of the invention or the scope of the annexed claims.

We claim:

1. A fastener comprising:

a cylindrical body, said body provided with external threads;

lonjgitudinal grooves situated on the exterior of said ody;

circumferential projections extending into said grooves formed by portions of said body;

locking pins engaged with said circumferential projections so as to be retained thereby in tight association therewith, said locking pins being slidably positioned in said grooves in longitudinal alignment therewith, said pins having an enclosed hollow axially extending, circumferentially continuous cavity therein for accommodating debris and sheared workpiece material accumulated during the axial displacement of the locking pins into an operative or fully locked position, said pins being provided with guide means for guiding said pins during axial displacement thereof in said grooves, said guide means being comprised of an integral projection extending longitudinally from the body of said pin, said projection having a tapered face; and

combination shearing and locating shoulders carried by said pins.

2. A fastener as described in claim 1 wherein the maximum diameter of the hollow portions of said pins as measured in a radial direction relative to the insert being such that the pins do not radially extend outwardly of the crests of the external threads of the fastener and the guide means of the locking pins have a maximum radial diameter across said guide means less than the minimum radial diameter of the bore of the workpiece.

3. A fastener as described in claim 1 wherein said longitudinal grooves are provided with a portion of the groove wall having a configuration corresponding to the configuration of the locking pins and said grooves being further provided with shoulder means for retaining said locking pins in tight association therewith.

4. A fastener as described in claim 1 wherein said pins are tubular in configuration and the maximum diameter of the hollow portions of said pins as measured in a radial direction relative to the insert being such that said pins do not radially extend outwardly of the crests of the external threads of the fastener, and wherein said longitudinal grooves are provided with a portion of the groove wall having a configuration corresponding to at least a part of the configuration of the locking pins, said grooves being further provided with shoulder means for retaining said locking pins in tight association therewith, and the guide 3 means of said locking pins being retained in tight association by the retaining shoulders provided by said longitudinal grooves.

5. A fastener as described in claim 1 wherein said pins are noncylindrical in configuration and do not radially extend outwardly of the crests of the external threads of the fastener.

6. A fastener as described in claim 1 wherein the longitudinal grooves have uniform side walls and the circumferential projections are comprised of displaced portions of the root of the external threads adjacent said grooves.

References Cited by the Examiner UNITED STATES PATENTS 573,044 12/1896 Seely 15123 3,233,645 2/1966 Neuschotz 85-8.8

FOREIGN PATENTS 622,227 2/ 1927 France.

4,840 8/1896 Norway.

CARL W. TOMLIN, Primary Examiner.

MARION PARSONS, JR., Examiner.

G. A. MILWICK, Assistant Examiner. 

1. A FASTENER COMPRISING: A CYLINDRICAL BODY, SAID BODY PROVIDED WITH EXTERNAL THREADS; LONGITUDINAL GROOVES SITUATED ON THE EXTERIOR OF SAID BODY; CIRCUMFERENTIAL PROJECTIONS EXTENDING INTO SAID GROOVES FORMED BY PORTIONS OF SAID BODY; LOCKING PINS ENGAGED WITH SAID CIRCUMFERENTIAL PROJECTIONS SO AS TO BE RETAINED THEREBY IN TIGHT ASSOCIATION THEREWITH, SAID LOCKING PINS BEING SLIDABLY POSITIONED IN SAID GROOVES IN LONGITUDINAL ALIGNMENT THEREWITH, SAID PINS HAVING AN ENCLOSED HOLLOW AXIALLY EXTENDING, CIRCUMFERENTIALLY CONTINUOUS CAVITY THEREIN FOR ACCOMMODATING DEBRIS AND SHEARED WORKPIECE MATERIAL ACCUMULATED DURING THE AXIAL DISPLACEMENT OF THE LOCKING PINS INTO AN OPERATIVE OR FULLY LOCKED POSITION, SAID PINS BEING PROVIDED WITH GUIDE MEANS FOR GUIDING SAID PINS DURING AXIAL DISPLACEMENT THEREOF IN SAID GROOVES, SAID GUIDE MEANS BEING COMPRISED OF AN INTEGRAL PROJECTION EXTENDING LONGITUDINALLY FROM THE BODY OF SAID PIN, SAID PROJECTION HAVING A TAPERED FACE; AND COMBINATION SHEARING AND LOCATING SHOULDERS CARRIED BY SAID PINS. 